ACARP ACARP ACARP ACARP
Coal Preparation

On-Line Vision Based Instrument to Measure Coal Flotation Froth Properties

Coal Preparation » Fine Coal

Published: October 99Project Number: C6043

Get ReportAuthor: Khoi Nguyen, Peter Holtham | JKMRC

Researchers have developed an on-line, vision-based prototype instrument to measure coal flotation froth properties.

Traditionally, optimal metallurgical performance in coal flotation circuits has been difficult to achieve due to the wide variety of process disturbances.

Although on-line analysis instruments have been available for the past 20 years, they are generally expensive to purchase and maintain, do not adequately detect process behaviour within flotation cells, and many contain nucleonic sources which present potential health and safety issues.

Over the past decade, the cost of image analysis hardware and software has become significantly lower, and new graphic file formats make it possible to handle and display images at resolutions beyond the capability of the human eye. Potentially, application of computer-based vision technology offers a number of advantages compared with other on-line analysis techniques:

  • The measurement is non-intrusive and non-contact (no interference with the process)
  • No mechanical parts are involved, such as sampling and de-aeration systems, so there are minimal maintenance requirements
  • Low capital cost, and
  • High sampling frequency

Project Objectives

The project's objectives are to:

  • Develop image analysis algorithms which can characterise flotation froth in terms of froth structure, bubble size and horizontal froth velocity (pulling rate)
  • Specify, develop and test a prototype machine vision system which can be used as a froth analyser to improve manual and automatic flotation control.

Findings

Researchers investigated the use of digital image analysis techniques to make quantitative measurements of surface froth characteristics, and applied the measurements to the evaluation and control of a coal flotation cell. A texture spectrum algorithm was developed to measure bubble size and froth structure, while an object-matching algorithm called pixel tracing was developed to measure froth velocity. The prototype instrument was successfully developed and evaluated on a Microcel flotation column at Peak Downs coal preparation plant.

Conclusions that can be drawn from the use of texture spectrum techniques are:

The texture spectrum method offers some important advantages compared with the other image analysis techniques:

  • The regional background noise of an image is reduced to a minimum
  • The conceptual approach is simple, reducing the amount of calculation required

The texture spectrum of a froth image provides a unique fingerprint of the froth. As a result, a classification algorithm using patterns of texture spectra could be developed to recognise froth structures. This algorithm was based on a set of standard froth structures which were collected under different process conditions at Peak Downs mine.

The height of the middle peak of the texture spectrum can be employed to measure the average bubble size of the froth image.

Conclusions that can be drawn from the development of the pixel tracing technique are:

Pixel tracing is suitable for automatic analysis where computational cycles are fixed because the technique is independent of the moving objects present in the scene. In traditional image analysis techniques where each object in the scene is traced individually, the computation time required for each analysis is different (in the worse case, it would take an infinite time).

The technique is simple but robust. It can measure froth speed and be used to predict the direction of the flow. However, in practice, only the principal direction of the froth has been considered in the analysis.

Where To From Here

The future work for this research project may be concentrated in:

  • Developing an advanced prototype instrument
  • Incorporating the prototype instrument into a flotation control strategy
  • Applying the techniques developed to other types of coal flotation cell, and
  • Using the digital image analysis to study the sub-processes occurring within the froth

 

Underground

Health and safety, productivity and environment initiatives.

Recently Completed Projects

C34019Longwall Bretby Cable Handling Monitoring With Fibre Optics

This project examined the potential of using fibre optic sensing tec...

C27049Mine Machine Radar Sensor Integration

The aim of this project was to develop an integrated radar sensor an...

C29007Innovative Coal Burst System To Investigate The Influence Of Confinement Loss And Pre-Conditioning On Coal Burst Mechanism

The challenges associated with designing and operating a safe and pr...

Underground

Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C33035High Water Recovery, Low Cost Desalination Using PV-Powered Membrane Capacitive Deionisation (Mcdi)

Capacitive deionization is a robust, energy efficient and cost effec...

C28035Topsoil Deficits In Site Rehabilitation Accelerated Transformation Of Spoils To Functional Soils

The incorporation of commercial biological amendments (compost, worm...

C34036Tyre Handler Testing Rig Stage 2: Lifting Trials

Tyre handling is a major source of risk in surface mining operations...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C34060In-Situ Investigation Of Coke Structure Formation Under Stamp Charged Coking Conditions

Stamp charged cokemaking has emerged as an effective technique to im...

C34062Improving The Classification Of Microstructure Distribution In Coke CT Images Using Deep Learning And Lineal Path Calculations

This project builds on a number of earlier projects that have helped...

C29071Source Of Variability Of Reactivity Of Coke In The CSR Test

The Coke Strength after Reaction (CSR) test is used worldwide to det...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL)

This third and final stage of this project was the culmination of a ...

C29069Low-Cost Catalyst Materials For Effective VAM Catalytic Oxidation

Application of ventilation air methane (VAM) thermal oxidiser requir...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community

NERDDC

National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook

NERDDC